Using the UltraSAM to Control the Robot Arm

USB port on UltraSAM can be used to control this robot arm. I will demonstrate you how to control it in python.

What you need:

• OWI Robot Arm: https://www.owirobot.com/robotic-arm-edge-1/
• OWI Robot Arm USB Interface: https://www.owirobot.com/products/USB-Interface-for-Robotic-Arm-Edge.html
• UltraSAM
• Python 2.7.3 for UltraSAM
• PyUSB: https://github.com/walac/pyusb
• libusb 1.0, libusb 0.1 or OpenUSB: your linux need one of them

Python Source Code:

[python]
import usb.core
import usb.util
import usb.backend.libusb1
import time

backend = usb.backend.libusb1.get_backend(find_library=lambda x: “/usr/lib/libusb-1.0.so”)
dev = usb.core.find(idVendor=0x1267, idProduct=0, backend=backend)
if dev is None:
raise ValueError(‘Device not found’)

STOP = [0,0]

GRIP_CLOSE = [1,0]
GRIP_OPEN = [2,0]
WRIST_UP = [4,0]
WRIST_DOWN = [8,0]
ELBOW_UP = [16,0]
ELBOW_DOWN = [32,0]
SHOULDER_UP = [64,0]
SHOULDER_DOWN= [128,0]

BASE_COUNTERCLOCKWISE = [0,1]
BASE_CLOCKWISE = [0,2]

duration = 1

def command2(cmd, light):
c = list(cmd)
c.append(light)
dev.ctrl_transfer(0x40,6,0×100,0,c,1000)

def command(cmd, light, duration):
c = list(cmd)
c.append(light)
dev.ctrl_transfer(0x40,6,0×100,0,c,1000)
time.sleep(duration)
c = list(STOP)
c.append(light)
dev.ctrl_transfer(0x40,6,0×100,0,c,1000)

def light(onoff):
command2(STOP,onoff)

def grip_close(onoff):
global duration
command(GRIP_CLOSE,onoff,duration)

def grip_open(onoff):
global duration
command(GRIP_OPEN,onoff,duration)

def wrist(value, onoff):
global duration
if int(value)0:
command(WRIST_UP, onoff, duration)
else:
command2(STOP, 0)

def elbow(value, onoff):
global duration
if int(value)0:
command(ELBOW_UP, onoff, duration)
else:
command2(STOP, 0)

def shoulder(value, onoff):
global duration
if int(value)0:
command(SHOULDER_UP, onoff, duration)
else:
command2(STOP, 0)

def base(value, onoff):
global duration
if int(value)>0:
command(BASE_COUNTERCLOCKWISE,onoff, duration)
elif int(value) command(BASE_CLOCKWISE, onoff, duration)
else:
command2(STOP, 0)

light(1)
time.sleep(5)
light(0)
grip_open(1)
grip_close(0)
time.sleep(5)
wrist(-1,1)
wrist(1, 0)
time.sleep(5)
elbow(-1,1)
elbow(1, 0)
time.sleep(5)
shoulder(-1,1)
shoulder(1, 0)
time.sleep(5)
base(-1,1)
base(1, 0)
[/python]